Trouble Starting 1983

[kevin g]

I have my '83 Vision running after rebuilding the carburetors and the petcock.  I had to make the little valves and cut new diaphragms for the petcock.  I went through the carburetors several times as I learned about them.  They were not that bad to start with and now I think they are in great order.

The bike runs great for the limited riding I have done.  The front brakes need attention and the tires are very old so I have just been around the neighborhood.  The problem is starting.  I have learned it wants full choke but it does not jump to life.  I have to crank a while and it seems to catch on one cylinder and run a bit and then finally catches the other cylinder.  The valves are in spec and the plugs are new and seem to get good spark.  I have tried 2 turns and 3 turns out on the idle mixture screws and it does not seem to make any difference.

I don't have much fuel in the tank, maybe 1-1/2 gallons or a bit more.  The YICS is hooked up and all vacuum and fuel lines are new.  Any suggestions on what to look for?

[fret not]

I recall some discussion on 'your technique for starting'.  I'm not sure of the title but there were several responses, mostly concerning how much choke to apply and how many twists on the throttle.  We all know that a well adjusted  motor should start and run better than one that needs a tune-up.  Another point to keep in mind regarding starting, the battery must be at very least 10.5V or the ignition will not fire.

[jefferson]

If you haven't had the starter apart for a good cleaning and installation of a new seal in the nose, I would recommend that. A healthy starter will keep from dragging down your cranking voltage and should spin faster as well.

[The Prophet of Doom]

You didn't mention syncing the carbs with a manometer.  That's an essential part of setting up to run well.

[kevin g]

The battery is a brand new AGM and the charging system puts 14.3V on it at idle and above and I have made sure it is fully charged before my attempts at starting.  Once running the bike runs well and the carbs are synchronized well.  My problem could be that it has been about 15 years since it ran and it is just teething problems, but...

Today I deduced that at start up the front cylinder does not fire right away.  It takes a little bit before it catches and then it warms nicely and runs fine.  The plugs are new and the spark seems strong.  The carbs have been gone through and rebuilt and seem to be in great shape.  The only difference I find is that the fuel level in the rear carb is a little higher than the front but it is actually too high according to the literature; I have not yet taken the time to adjust the rear float.  The YICS does not seem to have any leaks and the starting behavior is the same with the YICS ports plugged or connected properly.

Any further clues from anyone?  I have been over all of the obvious stuff and am no stranger to bikes, I have been doing my own work on them since 1977.

[Walt_M.]

How is the fuel pump? I read over your post and you said you have only a gallon or so in the tank which would put the fuel level close to or below the carbs. put another gallon in and see if it's better.

[jefferson]

Something else to check in the late firing cylinder would be compression. If the front carb was leaking to where it would be dry when you tried to start it that would cause a late firing issue too. A leak like that should be noticeable though.

[George R. Young]

The coil secondary resistance measured through the spark plug cap should be around 7.9 K-Ohms. Corrosion sometimes makes this resistance infinite, and makes starting harder.

[fret not]

This is why Tiger began making wire sets for the XZ.  He stressed to put new plug caps on new HT leads to the plugs because the older stuff begins to resist it's intended function.  I wonder if he still offers wires and cables.  I got a complete set when he was offering them, so I have the HT leads, new plug caps, and new cables from the battery to the solenoid, and from the solenoid to the starter.  This is not rocket science, so just about anyone can make up new wires and cables, but since Tiger was offering them I took advantage and bought some for one of my bikes.  He did a first rate job of making them, and used good parts and materials.